Dames & Moore, 1999 - USDA Forest Service

The field screening data combined with the laboratory analytical data from the Phase I sampling round
was used to characterize areas of common chemistry on the Site. The field screening program for the
Phase I1 RI was reduced to pH, specific conductance, and temperature for all surface water, groundwater,
and seep samples due to the results of the Phase 1 RI. The value of continuing oxidationfreduction
potential, dissolved oxygen, and ferrous iron during Phase I1 sampling efforts was considered limited as
general chemical characteristics of the site were not expected to change and were documented during the
Phase I activities.
Turbidity and dissolved oxygen were measured during Phase I1 at stations RC-6. RC-2, and RC-3.
Dissolved oxygen was measured by a quantitative chemical field test that allowed immediate titration of
the sample and recording of the dissolved oxygen result. The results were compared to dissolved oxygen
results measured by a field meter used in previous sampling rounds. The results obtained from the
quantitative chemical field test were consistent with those obtained from the field meter.
The field screening results for each sample were evaluated with the associated laboratory analytical data
to more completely evaluate site chemistry and to assist in the development of remedial action objectives
(RAOs).
3.9 TASK 9 - ECOLOGICAL SURVEYS
Referring to Figures 3.9-1 and 3.9-2, the ecological surveys conducted during the RI were primarily
focused on aquatic communities; however, terrestrial communities were investigated to provide general
characterizations of these communities and assess the potential for various terrestrial species that inhabit
the Site. The surveys were designed to collect site-specific information for the ecological risk assessment
and identification of potential injuries to natural resources. The results of the ecological surveys are
presented in Section 4.6.
3.9.1 Aquatic Biota
3.9.1.1 Background
Aquatic communities in the vicinity of the Site have been generally described in response to indications
of impacts from mine activities. In particular, Pacific Northwest Laboratory (Battelle) investigated
habitat, benthic macroinvertebrate communities, and fish populations in Railroad Creek from October
1989 to April 1990. The investigations were conducted to describe "baseline" conditions prior to the
Railroad Creek habitat enhancement activities. The reclamation activities were intended to increase the
productivity of Railroad Creek and to reduce the potential for an occurrence of a catastrophic erosion
event.
The post reclamation aquatic biota monitoring plan recommended the sampling of aquatic biota during
1990, 199 1, 1992, and 1996 (PNL, 1992). Post-reclamation aquatic monitoring was conducted in 199 1 by
Pacific Northwest Laboratory (Battelle) and in 1992 the USFS. A formal report was prepared for the
1991 data collection; however, the 1992 efforts, which included benthic macroinvertebrate and fish
sampling (tissue and population data) were apparently not compiled in a formal or draft report. The 1992
data were received in various forms directly and indirectly from the USFS. A review of these data
indicated that descriptions of sampling methods, sample locations, areas sampled, etc., were insufficient
for adequately describing the 1992 results or comparing the results to the 1991 and 1997 results. As such,
G:\rvpdata\OO~hpoNWoldmZ\riUddd~ 3-20 DAMES & MOORE
17693-005-019Uuly 19, 1999;2:07 PM.DRAR FINAL RI REPORT